Impeller



C. E.-WUENSCH IMPELLER Filed June 5, 1944 2. Sheets-Shae? 1 INVENTOR.CHARLES Ema WUENSCH July 23; 1946.

C. E. WUENSCH July 23, 1946.

IMPELLER Filed June 5, 1944 2 Sheets-Sheet 2 INVENTOR. CHARLES ERG WUEHCH BY r 1111111 ll/IIIIIIIIII Patented July 23; 1946 OFFICE f INIIELLERV Charles Erb Wuensch, Saratoga, Calif.

Application June 5, 1944, Serial No. 538,794

This invention relates to impellers, and more particularly to flexibleresilient blades for the impellers of centrifugal pumps.

- Among the objects of the invention is the prevention of injury to theblades of the impeller by oversize objects in the flow passing throughthe pump which would otherwise damage the pump and stop the operation.

Another object is to provide a blade that will flex topermitanobstruction to pass and then be restored to normal operativeshape by th centrifugal force of the operation.

A further object is to prevent excessive wear of the blades in pumpingabrasive materials.

Further objects are to provide a construction of maximum simplicity,economy and ease of assembly and contemplates such other and furtheradvantages as will appear to one skilled in the art as the descriptionthereof proceeds.

In attaining the foregoing objects, together with such further benefits,advantages and capabilities as may hereinafter appear and as inherentlypossessed thereby, there is disclosed byway of illustration only, theconstructions shown in the accompanying drawings. It is to beunderstood, however, that the invention is not limited to the examplesshown because the same may be embodied in further modifications withinthe spirit of the invention as set forth in the claim followingthedescription.

Referring to the drawings: c.

Figure 11s a side elevation of a centrifugal pump with a portion of thecasing broken away to disclose an impeller having blades constructed inaccordance with this invention.

Figure 2 is an enlarged longitudinal section of a. single blade of animpeller. j

Figure 3 is an enlarged front elevational view of a single blade.

- Figure 4 is an enlarged longitudinal section of a single bladerepresenting a modification.

Figure 5 is a fragmentary front elevation of a blade with a portion ofthe hub in section showing a detail of the attachment.

Figure 6 is an enlarged view of an im eller blade showing tangentialmounting and also il1us trating the positions assumed during operationand at rest.

Figure 7 is an enlarged view of a variant form of blade.

Referring now more particularly to the drawings, the impeller of thepresent invention com prises a series of radially extending blades 2which are securely mounted in or upon a hub 8 rotatlng Within a housingor casing which is generally .7 Claims. (01. 10 -115) 1 2 composed ofsides Xl and X-Z and acylindrical bowl .X-3. It is to be understood thatthe impeller and particularly the blades of the present invention areuseful especially in apparatus where fluids with abrasive materialsinsuspension are circulated or agitated. While: it is preferred to attachand dispose the blades 2 radially from the hub 8, it is to be understoodthat they may extend tangentially from the hub if desired as shown inFigures 6 and 7.

One construction or the blades 2 may be described as comprising a seriesof spaced metal wires orcables 1. arranged in a common plane extendingin spaced relation substantially across the entire width of the blade2.- The inner ends of the wires I are bent around an anchor key 3 andmaybe bent back upon themselves as at 4, to reinforce the lowerportionof the blade 2. In the event greater strength is desired. for the core,the wires or cables can be continued so that the ends of each wire Iterminates at the point of beginning. It is preferable, however, to givethereturning end a lateral twist so that all of the wires I lie in thesame plane and do not double back on each other as shown in Figure 1.-The outer ends of the wires may have eyelets 5" formed thereon or may beflattened or left as they are. The purpose of flattening the wires l orforming eyelets as shown in Figure 2 is to assist in anchoring a weight5. The weight 5 may be lead or any other suitable Weight which can becast or otherwise maintained around the outer ends of the wires orcables I. The advantage of casting the weight 5 around the outer ends ofthe wires l is to secure the assembly in a permanent arrangement whichwill then form a reinforcing core for the blade 2. The purpose ofweighting the outer ends of the blades is to give rigidity at this pointand also to stretch the blades slightly so as to minimize any tendencythrough centrifugal action to become larger in cross sectional diameteror area at the point of maximum flexure.

The external body of the blade 2 which forms it into a structure havinga rectangular horizontal section is composed of rubber or other highlyresistant and resilient compound I which can be vulcanized or otherwiseformed around and enclose the core and weight 5 to make thecomsubstances and eliminates corrosion when the impeller is idle.

In operation the bulblike end of the blade 2 presents an impact surfacesubstantially similar to that shown in the position I of Figure 1 and Vof Figure 6. However, if the blade is made inclined slightly forward asshown in the broken line IV of Figure 4 it will straighten out under theload of pumping and as a result of centrifugal force. Accordingly itwill present an impact surface corresponding substantially to the restposition shown in full lines in Figure 1. An advantage from incliningthe position of rest slightly forward resides in the fact that therewill be less slip stream loss in the operation.

In order to completely armour the impeller it will be desirable toarmour the exposed surfaces of the hub as shown at Ia. This will protectall of the exposed surfaces with a resilient armoured coating andlikewise prevent rusting during nonoperating periods.

I claim:

1. A flexible impeller blade for centrifugal pumps comprising incombination a flexible core extending substantially its entire length, aWeight secured to the outer end of said core to form an enlaregdbulb-like end, means at the other end of said core for securing theblade to a hub, and a flexible resilient covering for said core and saidweight said structure being capable of momentary distortion and flexingto pass an obstacle and return to its normal state without stopping theoperation of a pump.

2. A flexible impeller blade for centrifugal pumps comprising incombination a flexible core extending substantially its entire length, aweight secured to the outer end of said core to form an enlargedbulb-like end, means at the other end of said core for securing theblade to a hub, and a flexible resilient covering for the entire bladesaid structure bein capable of momentary distortion and flexing to passan obstacle and return to its normal state without stopping theoperation of a pump.

3. A flexible impeller blade for centrifugal pumps comprising incombination a flexible core extending substantially its entire length, aweight secured to the outer end of said core to form an enlargedbulb-like end, means at the other end of said core for securing theblade to a hub, and

a flexible internally reinforced resilient coverin for the blade saidstructure being capable of momentary distortion and flexing to pass anobstacle and return to its normal state without stopping the operationof a pump.

4. An impeller for centrifugal pumps comprising in combination a hub,and a plurality of blades flexible substantially from hub to tip, eachweighted at the outer end to form an enlarged bulb-like end and eacharmoured with a resilient flexible coating said structure bein capableof momentary distortion and flexing to pass an obstacle and return toits normal state without stopping the operation of a pump.

5. An impeller for centrifugal pumps comprising in combination a hub, acoating of resilient armour on said hub, and a plurality of bladesflexible substantially from hub to tip adapted to be held by said huband extended outward therefrom, each weighted at the outer end to forman enlarged bulb-like end and each armoured with a resilient flexiblecoating said structure being capable of momentary distortion and flexingto pass an obstacle and return to its normal state without stopping theoperation of a pump.

6. A flexible impeller blade for centrifugal pumps comprising incombination a sac of resilient flexible material adapted to be sealed atits inner end adjacent the hub to form a closed cavity therein, and afree moving weight in said cavity adapted to and capable of movinglongitudinally therein in response to external forces such as pressure,centrifugal force and distortion said structure being capable ofmomentary distortion and flexing to pass an obstacle and return to itsnormal state without stopping the operation of a P mp.

7. A flexible impeller blade for centrifugal pumps comprising incombination a sac of resilient flexible internally reinforced materialadapted to be sealed at its inner end adjacent the hub to form a closedcavity therein, and a weight in said cavity adapted to and capable ofmoving longitudinally therein in response to external forces such aspressure, centrifugal force and distortion said structure being capableof momentary distortion and flexing to pass an obstacle and return toits normal state without stopping the op eration of a pump.

CHARLES ERB WUE'NSCH.

